Narrowneck Reef Renewal

Photo courtesy International Coastal
Management

As the name suggests, Narrowneck is the narrow stretch of sand that splits the Nerang River from the southern end of Main Beach. This section of coast has a history of serious erosion, particularly as a result of storms.

In 1999, the City constructed an artificial reef offshore from Narrowneck using sand containers made from geotextile fabric. The reef reduces the erosion impact of large waves. As these waves cross the reef their intensity becomes less threatening to the beach. The reef also promotes a build-up of sand near the structure and this sand acts as a buffer to protect the beach during storms.

Like any infrastructure, the Narrowneck Artificial Reef has a design life and requires renewal to ensure the structure continues to function. In 2018 the City completed works to renew parts of the reef. Over 10 months, a total of 84 additional mega geotextile sandbags were placed around the existing structure using a specialised vessel. Watch our video to see how the containers were placed on the sea floor.

The locations of the new containers were influenced by physical modelling undertaken at the Queensland Government Hydraulics Laboratory, with some minor changes made to the shape of the renewed reef. The City carries out ongoing monitoring of the reef to ensure it continues to function as an effective coastal protection structure.

The Narrowneck artificial reef is a ‘Prohibited Anchorage Area’ and two yellow navigation buoys have been installed adjacent to the reef to mark the extents of the area.

Preventing vessels from anchoring on the reef will help mitigate potential safety hazards and ensure that the renewed reef is not damaged by anchors. Anchoring on the reef has been a leading cause of damage to the Geotextile Sand Containers.